U+FF70 "ー" Halfwidth Katakana-Hiragana Prolonged Sound Mark Unicode Character

Unicode Version 17.0

U+FF70 "ー" Halfwidth Katakana-Hiragana Prolonged Sound Mark is a typographic symbol used in Japanese writing to indicate a lengthened vowel sound, often appearing in katakana transcription of foreign words or in stylized text, such as "メニュー" for "menu". Its halfwidth design distinguishes it from the fullwidth version (U+30FC) and was originally created for compatibility with older text systems that used a narrow character grid, allowing it to fit neatly alongside halfwidth kana in contexts like teletype machines or early digital displays. While it serves the same phonetic purpose as its fullwidth counterpart, its narrower shape can sometimes affect text alignment or spacing in modern digital environments, and it remains part of the block of halfwidth characters inherited from legacy encoding standards like JIS X 0201.

General Properties

Code Point U+FF70
Version Added 1.1
Name Halfwidth Katakana-Hiragana Prolonged Sound Mark
Block Halfwidth and Fullwidth Forms
General Category Modifier Letter
Canonical Combining Class Not Reordered
Bidirectional Class Left To Right
Decomposition Type Narrow
Decomposition Mapping "ー" U+30FC Katakana-Hiragana Prolonged Sound Mark

Encodings

HTML Decimal Encoding ー
HTML Hex Encoding ー
UTF-8 Encoding 0xEF 0xBD 0xB0
UTF-16 Encoding 0xFF70
UTF-32 Encoding 0x0000FF70
C/C++/Java Escape \uff70

Unicode Properties

NFC Quick Check Yes
NFD Quick Check Yes
Numeric Type None
Numeric Value NaN
Line Break Conditional Japanese Starter
East Asian Width Halfwidth
Case Ignorable Yes
Changes When NFKC Casefolded Yes
NFKC Casefold "ー" U+30FC Katakana-Hiragana Prolonged Sound Mark
NFKC Simple Casefold "ー" U+30FC Katakana-Hiragana Prolonged Sound Mark
Script Common
Script Extensions Hiragana Katakana
Indic Syllabic Category Other
ID Start Yes
XID Start Yes
ID Continue Yes
XID Continue Yes
Diacritic Yes
Extender Yes
Alphabetic Yes
Vertical Orientation Rotated
Grapheme Base Yes
Grapheme Cluster Break Other
Word Break Katakana
Sentence Break OLetter